A machining condition of a wire electrical discharge machine includes many parameters such as a voltage, a wire tension, and a machining fluid pressure. Because there is an appropriate machining condition corresponding to an arrangement state, which is a setting condition of the wire electrical discharge machine and a workpiece, such as a workpiece thickness, a workpiece material, a wire material, a wire diameter, and a distance between upper and lower nozzles, the machining condition is changed depending on the arrangement state.
When a machining condition is added to an NC (Numerical Control) program, which is a machining program of a wire electrical discharge machine, any one of methods (1) to (4) described below is conventionally used.    (1) An operator of CAM selects a machining condition from a machining condition table such as a brochure, edits an NC program, and adds a command code that designates the machining condition.    (2) An operator of CAM retrieves a machining condition from a machining condition database connected to a PC (Personal Computer) that executes CAM software, and adds a command code that designates the machining condition to an NC program using a function of the CAM software.    (3) An operator of a wire electrical discharge machine selects a machining condition from a machining condition table such as a brochure, edits an NC program, and adds a command code that designates the machining condition.    (4) An operator of a wire electrical discharge machine retrieves a machining condition from a machining condition database connected to the wire electrical discharge machine, and adds a command code that designates the machining condition to an NC program using a function of the wire electrical discharge machine.
While the machining condition depends on the arrangement state, the operator of CAM does not know an actual arrangement state in the cases of the methods (1) and (2) described above and thus assumes a specific arrangement state to add a machining condition to an NC program. Therefore, when the operator of CAM and the operator of the wire electrical discharge machine do not share information correctly, a mismatch occurs between the arrangement state and the machining condition, which becomes a cause of a machining error.
In cases of the methods (3) and (4) described above, the operator of the wire electrical discharge machine needs to have a technique to add a command code that designates a machining condition to an NC program, and the lack of the technique becomes a cause of a machining error. Therefore, the methods (3) and (4) described above are not desirable when all the techniques are to be aggregated to the operator of CAM.